Episode Summary from aceshowbiz.com:
Flashbacks to Finch’s adolescence provide insight into his creation of The Machine. Also, the team receives the number of an already dying man, and Reese leaves the POI team behind in the aftermath of the war with the crime organization, HR.
Episode Summary from en.wikipedia.org:
After Carter’s death and the war with HR, Reese leaves the POI team and heads for Colorado, where his father had lived. Meanwhile, the Machine provides a new number to Harold, who at first is reluctant, but eventually accepts it on Root’s insistence. The number belongs to Arthur Claypool (Saul Rubinek), Harold’s close friend during his days at MIT. Claypool has been diagnosed with a brain tumor and is being monitored at the hospital. Shaw disguises herself as a doctor to get close to Arthur, who is kept under Secret Service protection as he inadvertently spills some top secret information about a project called Samaritan. Flashbacks to Harold’s teenage life are shown, where the initial idea for creating the Machine emerges in response to his father’s memory loss. Arthur’s wife, Diane (Camryn Manheim) tells Shaw that Arthur works for the NSA, and Collier’s group Vigilance tries to abduct him. Shaw, Harold, Arthur and his wife escape to a hotel, where Harold talks to Arthur to get more information about Samaritan. Arthur describes his involvement in the creation of an AI-like the Machine and his project shutdown. Fusco finds Reese in Colorado, where he tries to persuade Reese to come home before they fight outside the bar. As Arthur talks with Finch, he remembers that he buried his wife two years earlier, and Diane pretending to be Arthur’s wife reveals herself as Control. Her agents led by Hersh barge into the room and capture Shaw, Arthur, and Harold. Control threatens to kill either Arthur or Harold – whoever does not give up the location of his respective Machine. The episode ends with the Machine analyzing threats to its assets and itself, along with Arthur’s machine, Samaritan, having its status changed from “Deactivated” to “Unknown”.
Please use this thread to discuss the series’ fifty-sixth overall and third season eleventh episode Lethe. Rule: Please keep spoilers limited to those revealed during the series up to this episode only.